Osprey Team Latest

The Lyndon work party team were out in force again on Monday! It was a beautiful cold, bright day, the end of autumn slowly leaking into winter. The leaves have almost all fallen, the last few clinging vainly onto frost-covered branches. It was a perfect day for carrying out a bit of woodland management work!

The volunteers kept warm chopping small hazel and dragging the smaller bits to the fire, which was also a great way of keeping warm! Many of the thicker stems were cut into lengths suitable for use as stakes, and some of these stakes were then used to build wire fences around the hazel stumps. This is a precaution intended to prevent rabbits and deer nibbling the new shoots, which is detrimental to the subsequent regrowth of the coppice stools. Other stakes will be used for hedgelaying and willow weaving on other projects around the reserve.

The cleared area looks fantastic now that there is more space and light, and the view is improved too!

Thank you very much to Sarah Box for the following photographs.

The team are incredibly hard working and have accomplished a lot of tasks in recent weeks on the Lyndon reserve. Some other work that has been completed recently includes trimming the hedge and the entrance archway around the picnic area, clearing the willow regrowth in the front meadow, and creating a dead-hedge along the path to Teal hide, using material from the adjacent recently coppiced area.

Here are some photographs of the workers! Thanks to Sarah Box for these.

We all know that climate change is happening – there is no denying it. We are already seeing the effects that it is having on the planet. An increase in the severity of storms, freak weather events, loss of sea ice, a rise in sea level, longer heat waves, increased rainfall and consequent flooding, are just a few examples of the impact of a warming climate. The changes will affect the behaviour of all species, as they attempt to acclimatise to them. If they cannot adapt fast enough, or there is not enough genetic diversity to enable adaptation, then extinctions will happen. Species are already going extinct at an alarming rate. Scientists have estimated that we’re losing species at 1-10,000 times the natural background rate of one-five species per year, with dozens going extinct each day. We are currently undergoing the sixth mass extinction the planet has experienced – the biggest since the elimination of the dinosaurs 65 million years ago. Unlike previous mass extinctions, this one is caused by us.

The question has been raised more than once about the potential impact of climate change on the migration of ospreys. Of course, we can’t really know for sure, but can speculate based on what we do know. Animals that migrate do so due to the abundance of food, and must therefore time their movements to match those of their prey. They use environmental cues for the timing of their migration, and also for navigation, therefore any changes in these cues will undoubtedly have an effect. In terms of ospreys, they have to migrate to places where their prey, fish, are most plentiful. Fish are ectotherms, i.e. they depend on external sources of heat, and cannot regulate their own temperature internally. As such, their physiology is linked to the temperature of their environment. As temperatures decrease towards the end of summer, fish tend to migrate towards deeper water, making them impossible to catch, hence the need for ospreys to migrate to warmer climates.

A rise in temperature will influence the metabolism of the fish, which is likely to affect their movements. This means that fish in the UK could potentially remain available to ospreys for a longer period, and the beginning of the ospreys’ migration could thus be delayed. In some species, migration patterns have already altered, or indeed halted altogether, as a result of changes to their environment and the movement of their prey. However, having the ospreys stay longer in the UK and even potentially all year round is not a good thing at all. Migration has a role in reducing the occurrence and spread of diseases and infections, as individuals are vacating potentially contaminated habitats, and are separated from one another during the migration process. Also, diseased individuals are less likely to survive any long-distance travel, i.e. only the strong survive, therefore leaving the population more or less healthy. Consequently, staying sedentary and not migrating can lead to increased incidences of disease, which can then be transmitted to others in the population, and infect offspring through the breeding of infected individuals. In closely knit populations, and particularly those that contain low genetic diversity, a disease outbreak could wipe out an entire local population.

Migration is an important, innate process that certain species have been undertaking for thousands of years. Almost 20% of all bird species migrate. It is a necessary part of their lives, and that of their prey species. If these normal patterns, and indeed other aspects of animal behaviour, become disrupted, the consequences could be far reaching and there may be more serious and complicated effects that we cannot yet predict.

Work parties have been taking place at Lyndon every Monday since the beginning of October. Despite the rain, yesterday was no exception! We thought that the forecasted torrential downpour might, understandably, put some people off, but how wrong could we be! We still had a group of 17 hardy troopers who turned up to work in the wet.

Luckily for us, it wasn’t as bad as predicted, and the really heavy rain waited until we had packed the tools away and come inside for a welcome lunch of Paul’s soup and Jan’s cakes. Whilst we worked, the rain was mostly just a persistent drizzle. We still got completely soaked, of course, and some of us ended up covered in slimy green algae that clung to the bases of the trees near the water’s edge. All in a day’s work, though!

The task yesterday was to re-coppice two different areas of small willow and hazel regrowth. We split the group into two teams, and coppiced two small areas – willow in one, hazel in the other. The purpose of this work was to open up the view and improve light penetration to the ground. Some of the larger stems (2-3 inches diameter) were put aside and they will be used in the future as stakes for hedge-laying and willow weaving.

Thank you to everyone who turned up yesterday despite the inclement weather!

Our satellite-tracked osprey, 30(05), still appears to be having a relaxing winter in Senegal! She doesn’t have to travel far at all in the winter to get what she needs, and can thus conserve her energy, replenish her condition and be ready for her northwards journey in the spring. She has her little patch of beach to call her own, which she will defend from other ospreys, as she will defend her nest in the UK. However, there are a lot of other ospreys in the general area where 30 winters, and they are all relatively tolerant of each other. Much more so than in the breeding season in England, anyway! 30 only has to feed herself twice a day, but even then she doesn’t have to go far, as the sea is right there and the fish are plentiful. The furthest she went to catch a fish over the past twenty days was just over a mile!

In the map below, you can see 30’s movements over the past month, and how little she has had to move. It seems that she went on a little trip inland on 5th November, but was back at her spot on the beach within three hours. Perhaps she fancied a change of scenery!

Here is part two of Ken Davies’ fictional winter diary of Ozzie the osprey!

November 2016

Ozzie’s winter routine down in Gambia has not changed much since we last heard a few weeks ago. He spends a lot of time on favourite sand banks and tree perches, watching the comings and goings of other Ospreys, until he feels it’s time to go and catch a fish in the calm sea waters or the nearby mangrove creeks and lagoons. His life here is easy-paced, relaxed and calm. Most local people in the bustling village of Tanji are too busy to spend time looking at Ozzie, but the children from the local school, led by their teacher Isatou and their friendly bird-man JJ, often come down to the beach to see him. They like all the birds, and have learnt to recognise most of them now, thanks to JJ. They see all the other Ospreys, and call out ‘kulanjang’ whenever they see one – the word meaning ‘fish eagle’ in their own Mandinka dialect. It’s always a special moment when someone spots Ozzie, with his blue leg-ring and transmitter antenna showing well. Everyone wants to be the first to see him and shout ‘Ozzie, it’s Ozzie’ so that all the children can turn their eyes towards him.

The girl called Kaddy tries especially hard – she was the person who spotted Ozzie’s arrival at Tanji last winter, when Ken and his friends were here.

But today Ozzie is not here on the beach at Tanji. The small group search for a while, checking each Osprey as it flies in from the sea, or over their heads from further inland. He will not be far away, JJ tells them. Before they go, they spend some time collecting up some old fishing nets and other discarded equipment which has been left on the beach. All this is dangerous to the birds, because the tide will take it out into the sea, where it will float just below the surface and trap any bird, including an Osprey, which might dive into the water. Ozzie had a narrow escape himself last year, when he almost got tangled in a net during his migration. JJ collects all the old pieces of net and rope and the children take them away in a wheelbarrow. At least there will be no accidents on this beach now.

The next time JJ brings a group to the beach Ozzie is still missing. The children are beginning to get worried. ‘Where has he gone?’ they ask JJ. ‘It is nowhere near time for him to go back to Rutland Water yet, so where can he be?’

‘Don’t worry,’ JJ replies, ‘Ozzie has done this before. I am sure he has decided to take a little trip to see a bit more of Gambia. He will be back soon.’

JJ was absolutely right. Ozzie had indeed gone on a little adventure. Early one morning just a couple of days ago, he left his favourite bare tree near Tanji beach and flew out to sea. He caught a silvery fish, but instead of taking it back to the shore, as he usually did, he landed on a tiny island – no more than a scrap of sand, shingle and a few stunted bushes – and ate his fish there. The island is called Bijoli, a favourite haunt of Ospreys, terns of many species, and wading birds spending the winter months thousands of miles away from their Arctic breeding grounds. The sea is slowly eroding Bijoli away – soon there will be nothing left.

After a good long rest, Ozzie again takes to the air. The breeze is light, the sun hot on his back. It is perfect for soaring, circling, higher and higher, until Bijoli is just a speck in the Atlantic Ocean a mile below him. He lets the wind carry him, until he is at the wide mouth of the great Gambia River, where it flows relentlessly into the sea. He sees the busy ferry boats crossing from one side of the river mouth to the other, laden with people packed closely together, and cars and trucks.

Ozzie knows exactly where he is, and where he is going. He has made this little trip in previous years, and the familiar landmarks, perches and fishing places are imprinted on his memory just like those back at Tanji and at Rutland Water. His first stop is a vast wetland area called Bulok on the south bank of the river, with trees, lagoons, ditches and muddy flat areas – a perfect habitat for the thousands of birds which live there. Many Ospreys from Europe make this their winter home. They see Ozzie approaching, and two of them go up to meet him.

There is some initial suspicion when a strange Osprey appears in their winter territory, but they soon learn he is not a threat and they return to their perches. Ozzie is watched by other birds as he continues up river – a Dark Chanting Goshawk turns its head upwards, but it does not leave its perch on a telegraph pole. African Jacanas – the famous ‘lily trotters’ – pause momentarily, one enormous spindly foot raised over a spreading lily leaf, before carrying on with their search for food. A Violet Turaco, a blaze of colour, sees him too, and so does a Black-headed Heron, standing like a statue in the shallows.

As evening approaches, Ozzie circles over a pool surrounded by mangroves. Fishermen are casting their nets, and large shoals of glistening silvery fish are jumping out of the water in a frenzy. Ozzie moves a little further away before diving into the water and catching a fish at his first attempt. He lands in a mangrove tree to eat and rest. It is too late to go back to Tanji now. He will stay here for the night.

The next afternoon, on wooden seats at the end of a creaking jetty, with narrow fishing boats tied alongside, three friends from England are enjoying a cold Gambian beer on the edge of the Gambia River, at Tendaba Camp. In the mid-distance, playfully rolling and arcing in the wide river’s central flow, two or three dolphins ripple the water, while an Osprey beats slowly up and down, head downward, seeking a fish disturbed by the dolphins. The three friends study the Osprey. At times there is a definite impression of a small antenna protruding from its back feathers, but sadly it does not come any closer, and they cannot draw any conclusions before it turns and heads purposefully back down river towards the sea, and out of sight. ‘I wonder who’s tracking that one,’ says one of the three. He walks back along the jetty to the bar, and orders three more beers……………

It has been a few days since JJ took the children from Tanji School down to the beach, but one day he calls at the school to collect them and give them another chance to see if Ozzie has returned. Binta, Kaddy and Penda, Sarjo and Amadou – JJ knows all their names, and is so pleased by their enthusiasm. They arrive at the beach and take it in turn to scan the beach and the sand banks with the binoculars.

There are one or two false starts. ‘That’s him!’ ‘No, it’s not.’ ‘Let me try.’ ‘My turn with the telescope!’

It all goes quiet for a while. Are they going to be disappointed again?

Just when it’s almost time to go home, JJ turns and looks at Ozzie’s tree behind them, just in time to see an Osprey lift off from the top branch and fly towards them. JJ says nothing until the bird is almost over the heads of the group on the beach, and then he calls ‘Look, everyone, who is this?’

Immediately everyone is looking up through their binoculars. Kaddy is the first to speak.

‘Ozzie, it’s Ozzie,’ she shouts. She’s right. Ozzie is back at Tanji, after his little adventure, just like JJ said he would be. There are smiles, whoops and shouts. Ozzie is back, and all is well.